Pump device and method for at least locally sealing the pump device

ABSTRACT

The invention relates to a pump device for pumping a fluid, comprising a hydraulic housing (2), a pump ring support (5) which is arranged in the hydraulic housing (2), an elastic pump ring (3) which is arranged between the pump ring support (5) and the hydraulic housing (2) in the radial direction (RR), and a separating chamber pin (4), wherein the pump ring (3) can be pressed in the radial direction (RR) against an inner wall surface of the hydraulic housing (2) by means of the separating chamber pin (4) in order to produce an at least local seal on the hydraulic housing (2), and wherein the hydraulic housing (2) has a radial offset section (6), along which an offset element that is formed on the separating chamber pin (4) or a separate offset element that interacts with the separating chamber pin can be introduced in the axial direction (AR) and thus offsets the separating chamber pin (4) and the pump ring (3) in the radial direction.

The invention relates to a pump device and a method for at least locally sealing the pump device, particularly on an inner wall surface of the hydraulic housing while using a separating chamber pin.

Type-defining pump devices are well-known from the prior art. For example, publication WO 2016/173800 A1, stemming from the applicant, discloses a corresponding pump device for pumping and/or conveying fluids with a hydraulic housing, a pump ring support, and a pump ring, which is offset by means of a separating chamber pin, which is also characterized as a clamping element, in order to separate, with sealing, pump chambers from one another and/or a suction side from a pressure side of the pump. The pump ring is characterized also as a membrane by technical experts. During assembly, the separating chamber pin is pressed axially into the elastic pump ring and, in doing so, its free front edge displaces the pump ring in both the axial and radial direction, wherein the radial offset produces a seal on the inner wall surface of the hydraulic housing. It is problematic in this case that axial loads are exerted onto the pump ring, caused by the axial introduction and/or displacement of the separating chamber pin, and these axial loads can damage the pump ring or lead to an unequal stress ratio within the pump ring. The sealing tightness is then not ensured or at least not over the service life of the pump device.

Therefore, the object upon which the invention is based is to provide a pump device, in which the sealing of the pump ring can take place on the hydraulic housing, wherein the axial forces acting on the pump ring during assembly are eliminated or at least reduced.

This object is achieved by the combination of features according to claim 1.

According to the invention, a pump device is proposed for pumping a fluid, said pump device comprising a hydraulic housing, a pump ring support which is arranged in the hydraulic housing, an elastic pump ring which is arranged between the pump ring support and the hydraulic housing in the radial direction, and a separating chamber pin.

The pump ring can be pressed in the radial direction against an inner wall surface of the hydraulic housing by means of the separating chamber pin, to produce an at least local seal on the hydraulic housing, in order to separate pump chambers of the pump device from one another. The hydraulic housing has a radial offset section, along which an offset element that is formed on the separating chamber pin or a separate offset element that interacts with the separating chamber pin can be introduced in the axial direction, and thus offsets the separating chamber pin and the pump ring in the radial direction, in order to produce a radial compression of the elastic pump ring on the hydraulic housing.

The provision of the radial offset section provided on the hydraulic housing and of the offset element acting on the separating chamber pin makes it possible to guide the separating chamber pin initially completely or substantially completely through the pump ring without exerting any significant axial force onto the pump ring. The pressing of the pump ring onto the hydraulic housing in the radial direction can advantageously be effected by the offset element that interacts with the radial offset section once the separating chamber pin extends the pump ring in the axial direction. The axial force, which leads to an undesirable local movement of the pump ring in the axial direction, and which was previously exerted onto the pump ring during insertion of the separating chamber pin, can be avoided.

In an advantageous design variant, the offset element is formed as one piece on the separating chamber pin, particularly on its axial edge section, and offsets the separating chamber pin in the radial direction as soon as it interacts with the radial offset section. The interaction can be achieved, for example, in that the offset element is displaced over the radial offset section in the axial direction and, in doing so, offsets the separating chamber pin in the radial direction. The one-piece design means that additional components can be eliminated.

Furthermore, a design of the pump device is characterized in that a radially outer insertion plane of a shell surface of the separating chamber pin extends, without overlap, in the radial direction as relates to a pump ring plane of the pump ring, said pump ring plane to be offset outward radially in the radial direction when the separating chamber pin is in the preassembled state. The separating chamber pin can hereby be guided to the pump ring in the axial direction without making contact therewith or at least without exerting an axial force onto said pump ring. The insertion plane and the pump ring plane can also coincide. The preassembled state is the state in which the separating chamber pin is introduced into the elastic pump ring, but radial compression has yet to be exerted onto the pump ring.

Furthermore, a design of the pump device, in which the separating chamber pin can be offset in the radial direction, in a state in which the pump ring is completely extended in the axial direction, is advantageous in order to simultaneously press the elastic pump ring against the inner wall surface of the hydraulic housing over its entire effective axial length. To this end, the separating chamber pin has a sufficient axial length such that it is initially guided completely through the pump ring in the axial direction and only subsequently offset as a whole in the radial direction. Thus, there are no axial forces acting on the pump ring which could damage it during insertion of the separating chamber pin.

In one design variant of the pump device, it is provided that the radial offset section of the hydraulic housing is formed as a radial stage. In particular, the radial stage is provided on an axial insertion section of the hydraulic housing for the separating chamber pin such that the separating chamber pin can interact with the radial stage in the axial outer region, i.e. spaced apart from the pump ring axially, in order to effect the radial offset of the separating chamber pin and the pump ring.

In one refinement, the pump device is characterized in that the radial stage and the offset element formed on the separating chamber pin have a corresponding angled ramp, by means of which the separating chamber pin can be displaced in the axial direction in order to simultaneously produce the radial offset of the separating chamber pin and of the pump ring. Thus, the separating chamber pin can be pushed axially, as before, into the pump ring, while the angled ramps of the radial stage and of the offset element offer a guide for the separating chamber pin, said guide automatically offsetting the separating chamber pin in the radial direction upon complete insertion into the final assembly position.

Furthermore, one exemplary embodiment of the pump device provides that the hydraulic housing forms a mount for the separating chamber pin on a side axially opposite the radial offset section as relates to the pump ring support. The mount has an insertion ramp extending at an incline in the radial direction, by means of which the separating chamber pin can be displaced and simultaneously offset in the radial direction. The separating chamber pin can be offset in the radial direction on a second axial side via the inclined insertion ramp of the mount, and consequently the separating chamber pin can be offset over its entire axial length. A design in which the inclined insertion ramp and the angled ramps have the same angle as relates to an axial extension of the separating chamber pin is advantageous such that the separating chamber pin can be offset axially in the radial direction, the same on both sides.

In an alternative variant, the pump device further comprises at least one insertion element, the radial extension of which is dimensioned greater than that of the radial offset section. The at least one insertion element can be inserted into the radial offset section in the axial direction and, in doing so, offsets the separating chamber pin and the pump ring exclusively in the radial direction. This means that the number of parts is greater due to use of an insertion element, but conventional standardized separating chamber pins can be used which are offset in the radial direction via the insertion element. An offset element formed on the separating chamber pin can then be eliminated.

In one refinement of the pump device, the hydraulic housing has two axially opposite radial offset sections and two insertion elements as relates to the pump ring support, wherein a respective insertion element is insertable into a respective radial offset section in the axial direction and, in doing so, offsets the separating chamber pin and the pump ring from two axially opposite sides, exclusively in the radial direction. By means of this solution with two insertion elements, the number of parts is again increased, but the pump ring can experience a uniform radial compression, from two axial sides, on the hydraulic housing due to the radial offset of the separating chamber pin.

The disclosure additionally comprises the method for the at least local sealing of the previously described pump device, comprising a hydraulic housing and a drive shaft extending within the hydraulic housing in the axial direction, a pump ring support arranged between the hydraulic housing and the drive shaft in the radial direction, an elastic pump ring arranged between the pump ring support and the hydraulic housing in the radial direction, and a separating chamber pin. With the method, the separating chamber pin is initially positioned in a state in which the pump ring is completely extended in the axial direction and subsequently offset in the radial direction. The pump ring is hereby pushed or pressed against the inner wall surface of the hydraulic housing in order to produce the at least local seal.

One design of the method provides that an offset element that is formed on the separating chamber pin or a separate offset element that interacts with the separating chamber pin is introduced in the axial direction, along the radial offset section of the hydraulic housing, and thus offsets the separating chamber pin and the pump ring in the radial direction.

The method further comprises the variant that the radial offset section formed as the radial stage and the offset element formed on the separating chamber pin have the corresponding angled ramp, by means of which the separating chamber pin is pushed in the axial direction in order to simultaneously offset the separating chamber pin and the pump ring in the radial direction.

For the design variant in which the hydraulic housing forms the mount for the separating chamber pin on the side axially opposite the radial offset section as relates to the pump ring support and has the insertion ramp extending at an incline in the radial direction, the method provides that the separating chamber pin is pushed in the axial direction via the insertion ramp extending at an incline and is simultaneously offset in the radial direction. The pump ring as a whole is hereby pressed against the inner wall surface of the hydraulic housing from its two axially opposite sides.

With the solution in which the pump device has at least one insertion element, the radial extension of which is dimensioned greater than that of the radial offset section, the insertion element is inserted, in one design variant of the method, into the radial offset section in the axial direction and, in doing so, offsets the separating chamber pin and the pump ring exclusively in the radial direction.

Furthermore, the method comprises the exemplary embodiment in which the hydraulic housing has two axially opposite radial offset sections and two insertion elements as relates to the pump ring support, wherein a respective insertion element is insertable into a respective radial offset section in the axial direction and, in doing so, offsets the separating chamber pin and the pump ring from two axially opposite sides, exclusively in the radial direction.

Other advantageous further embodiments of the invention are characterized in the dependent claims and/or are shown in more detail in the following by means of the figures, along with the description of the preferred embodiment of the invention. The following is shown:

FIG. 1 a lateral sectional view of a section of a conventional pump device not in accordance with the invention;

FIG. 2a a lateral sectional view of a section of a pump device in a first design variant;

FIG. 2b the lateral sectional view of the section from FIG. 2a with the separating chamber pin mounted;

FIG. 3a a lateral sectional view of a section of a pump device in a second design variant;

FIG. 3b the lateral sectional view of the section from FIG. 3a with the separating chamber pin mounted;

FIG. 4 sectional view A-A from FIGS. 2a and 3 a;

FIG. 5 sectional view B-B from FIGS. 2b and 3 b;

Equivalent reference numerals indicate the same technical elements in all views.

FIG. 1 shows a lateral sectional view of a section of a conventional pump device 100 with a hydraulic housing 101, a pump ring support 103 arranged in the hydraulic housing 101, as well as an elastic pump ring 102 arranged in between. The pump device 100 is not necessarily prior art but instead only represents the object achieved by the invention. During assembly, a separating chamber pin 104 is pushed into the pump ring 102 in the axial direction and presses, with its free axial and, against the pump ring 102 simultaneously in the axial and radial direction for compression on the inner wall surface of the hydraulic housing 101, wherein damage can occur to the pump ring 102 due to the axial force effect.

FIGS. 2a and 2b show a first design variant of a section of the pump device 1 in a lateral sectional view, wherein the radial direction RR extends vertically and the axial direction AR extends horizontally. Additional components of the pump device 1, such as the drive motor or the drive shaft, have been omitted for the sake of clarity. The pump device 1 comprises, as essential components, the hydraulic housing 2 formed from several parts, the pump ring support 5, the elastic pump ring 3 arranged between the pump ring support 5 and the hydraulic housing 2 in the radial direction, and the separating chamber pin 4. FIG. 2a shows the separating chamber pin 4 in the preassembled state; FIG. 2b shows it in the final assembly state. A connection 20 for conveying fluid is shown on an outer side of the hydraulic housing 2. The hydraulic housing 2 can also partly be replaced by a flange.

The hydraulic housing 2 has an insertion channel 12 for the separating chamber pin 4, on the first axial side of which the radial offset section 6 formed as the radial stage is provided and on the second axial side of which the mount 9 for the separating chamber pin 4 is provided. The radial stage of the radial offset section 6 on the hydraulic housing 2 forms an angled ramp 7, by means of which the separating chamber pin 4 can be offset in the radial direction. In the preassembled position according to FIG. 2a , the radially outer insertion plane EE of the shell surface of the separating chamber pin 4 extends parallel to and slightly apart from the pump ring plane PE of the pump ring 3 in the radial direction such that the separating chamber pin 4 can be guided to the pump ring 3 in the axial direction, in the state shown in FIG. 2a , without an axial force being exerted onto the pump ring.

The offset element is formed, in one piece, on the separating chamber pin 4 as a local thickening 14 in the axial end section. The transition between the thickening 14 and the rest of the separating chamber pin 4 likewise occurs via an angled ramp 8, which is formed according to the angled ramp 7 of the radial stage. If the separating chamber pin 4 is pushed in the axial direction AR into its final assembly position according to FIG. 2b , the separating chamber pin 4 is offset radially outward about the radial extension of the thickening 14 of the separating chamber pin 4 and simultaneously presses the elastic pump ring 3 against the inner wall surface 21 of the hydraulic housing 2, as shown in FIG. 2b . To ensure a radial offset of the separating chamber pin 4 over its entire axial length, the mount 9 has the insertion ramp 10 at an angle according to the angled ramp 7 of the hydraulic housing 2. To this end, the separating chamber pin 4 forms a conical taper 11 on its free axial end, said taper being formed according to the insertion ramp 10 in the design shown. In FIG. 2b , the separating chamber pin 4 is pushed completely into the mount 9; the seal is formed between the pump ring 3 and the inner wall surface 21.

FIGS. 3a and 3b show an alternative variant of the pump device 1 in sections as lateral side views, wherein the same features as in FIGS. 2a and 2b are not repeated, but nevertheless should be considered disclosed. As a variant of the solution according to FIGS. 2a and 2b , the radial offset section 6 of the hydraulic housing 2 is at a right angle and formed identically on both axially opposite sides of the pump ring support 5. In the preassembled position according to FIG. 3a , the separating chamber pin 4 is already positioned with the pump ring 3 completely extended in the axial direction. The insertion plane EE and the pump ring plane PE coincide without spacing in the exemplary embodiment shown. A respective insertion element 22 is pushed axially into the radial offset sections 6 on both sides, the radial extension of which is dimensioned greater than that of the radial offset sections 6. On their edge sections facing the separating chamber pin 4, the insertion elements 22 each have a chamfer 23 in order to be more easily inserted and, in doing so, to offset the separating chamber pin 4 and the elastic pump ring 3 exclusively in the radial direction RR and press them against the inner wall surface 21 of the hydraulic housing 2.

FIGS. 4 and 5 show sectional views A-A of FIGS. 2a and 3a and B-B of FIGS. 2b and 3b , respectively, wherein the radial offset of the separating chamber pin 4 and the hereby effected pressing of the pump ring 3 against the inner wall surface 21 of the hydraulic housing 2 can be seen. Furthermore, radial channels 24 are provided on the hydraulic housing 2 for establishing a fluid connection with a pump chamber between the inner wall surface 21 of the hydraulic housing 2 and the pump ring 3, wherein the pump ring 3 separates the two radial channels 24, as viewed in the circumferential direction.

Even if not shown in the figures, an alternative design also comprises combining the two exemplary embodiments according to FIGS. 2a and 2b with one another and providing the solution according to FIGS. 3a, 3b with rectangular radial offset sections 6 on an axial side and an insertion element 22 on the opposite axial side and providing a solution according to FIGS. 2a, 2b with insertion 9, wherein the separating chamber pin 4 is formed on its two axial sides according to the exemplary embodiments shown. 

1. A pump device for pumping a fluid, comprising a hydraulic housing (2), a pump ring support (5) which is arranged in the hydraulic housing (2), an elastic pump ring (3) which is arranged between the pump ring support (5) and the hydraulic housing (2) in the radial direction (RR), and a separating chamber pin (4), wherein the pump ring (3) can be pressed in the radial direction (RR) against an inner wall surface of the hydraulic housing (2) by means of the separating chamber pin (4) in order to produce an at least local seal on the hydraulic housing (2), and wherein the hydraulic housing (2) has a radial offset section (6), along which an offset element that is formed on the separating chamber pin (4) or a separate offset element that interacts with the separating chamber pin (4) can be introduced in the axial direction (AR) and thus offsets the separating chamber pin (4) and the pump ring (3) in the radial direction.
 2. The pump device according to claim 1, characterized in that the separating chamber pin (4) can be offset in the radial direction (RR), in a state in which the pump ring (3) is completely extended in the axial direction (AR), in order to simultaneously press the pump ring (3) against the inner wall surface of the hydraulic housing (2) over its entire effective axial length.
 3. The pump device according to claim 1, characterized in that the radial offset section (6) of the hydraulic housing (2) is formed as a radial stage.
 4. The pump device according to claim 1, characterized in that the offset element is formed as a single piece with the separating chamber pin (4).
 5. The pump device according to claim 1, characterized in that a radially outer insertion plane (EE) of a shell surface of the separating chamber pin (4) extends, without overlap, in the radial direction (RR) as relates to a pump ring plane (PE) of the pump ring (3), said pump ring plane to be offset outward radially in the radial direction when the separating chamber pin (4) is in the preassembled state.
 6. The pump device according to claim 3, characterized in that the radial stage and the offset element formed on the separating chamber pin (4) have a corresponding angled ramp (7, 8), by means of which the separating chamber pin (4) can be displaced in the axial direction (AR) in order to simultaneously produce a radial offset of the separating chamber pin (4) and of the pump ring (3).
 7. The pump device according to claim 1, characterized in that the hydraulic housing (2) forms a mount (9) for the separating chamber pin (4) on a side axially opposite the radial offset section (6) as relates to the pump ring support (5), wherein the mount (9) has an insertion ramp (10) extending at an incline in the radial direction (RR), by means of which the separating chamber pin (4) can be displaced and simultaneously offset in the radial direction (RR).
 8. The pump device according to claim 1, further comprising at least one insertion element (22), the radial extension of which is dimensioned greater than that of the radial offset section, and which can be inserted, in the axial direction (AR), into the radial offset section and, in doing so, offsets the separating chamber pin (4) and the pump ring (3) exclusively in the radial direction (RR).
 9. The pump device according to claim 8, characterized in that the hydraulic housing (2) has two axially opposite radial offset sections and two insertion elements (22) as relates to the pump ring support (5), wherein a respective insertion element (22) is insertable into a respective radial offset section in the axial direction (AR) and, in doing so, offsets the separating chamber pin (4) and the pump ring (3) from two axially opposite sides, exclusively in the radial direction (RR).
 10. A method for at least locally sealing a pump device for pumping a fluid, the pump device comprising a hydraulic housing (2), a pump ring support (5) which is arranged in the hydraulic housing (2), an elastic pump ring (3) which is arranged between the pump ring support (5) and the hydraulic housing (2) in the radial direction, and a separating chamber pin (4), the method comprising initially positioning the separating chamber pin (4) in a state in which the pump ring (3) has complete extension in an axial direction and offsetting the separating chamber pin in the radial direction (RR) to press the pump ring (3) against the inner wall surface (21) of the hydraulic housing (2) and produce an at least local seal.
 11. The method according to claim 10, wherein the hydraulic housing (2) has a radial offset section, the method further comprising introducing an offset element that is formed on the separating chamber pin (4) or a separate offset element that interacts with the separating chamber pin (4) along the radial offset section in the axial direction (AR) to offset the separating chamber pin (4) and the pump ring (3) in the radial direction (RR).
 12. The method according to claim 11, wherein the radial offset section of the hydraulic housing is formed as a radial stage and the radial stage and the offset element formed on the separating chamber pin (4) have a corresponding angled ramp (7, 8), the method further comprising displacing the separating chamber pin (4) via the angled ramp in the axial direction in order to simultaneously offset the separating chamber pin (4) and the pump ring (3) in the radial direction (RR).
 13. The method according to claim 10, wherein the hydraulic housing (2) forms a mount for the separating chamber pin (4) on a side axially opposite the radial offset section as relates to the pump ring support (5), and the mount (9) has an insertion ramp (10) extending at an incline in the radial direction (RR), the method comprising displacing the separating chamber pin (4) in the axial direction (AR) via the insertion ramp (10) extending at an incline to be simultaneously offset in the radial direction (RR).
 14. The method according to claim 10, wherein the pump device (1) has at least one insertion element (22), the radial extension of which is dimensioned greater than that of the radial offset section, the method comprising inserting the at least one insertion element in the axial direction (AR), into the radial offset section and, in doing so, offsetting the separating chamber pin (4) and the pump ring (3) exclusively in the radial direction (RR).
 15. The method according to claim 10, wherein the hydraulic housing (2) has two axially opposite radial offset sections and two insertion elements (22) as relates to the pump ring support (5), the method further comprising inserting a respective insertion element (22) into a respective radial offset section in the axial direction (AR) and, in doing so, offsetting the separating chamber pin (4) and the pump ring (3) from two axially opposite sides, exclusively in the radial direction (RR). 